Lighting sewing machines and the like



y 1940. P. A. CULLMAN LIGHTING SEWING MACHINES AND THE LIKE Filed Sept.3, 1936 4 Sheets-Sheet l INVENTOR fifiaall/zaa/z ATTORNEY July 16, 1940.P. A. CULLMAN LIGHTING SEWING MACHINES AND THE LIKE Filed Sept. 3, 19364 Sheets-Sheet 2 a m w RNVENTOR VfQW 4&CZZ7IZCZIC ATORNEY July 16, 1940.P, A, CULLMAN 2,208,522

LIGHTING SEWING MACHINES AND THE LIKE Filed Sept. 3, 1936 4 Sheets-Sheet5 'I II/[Z g gBY ATTORNEY y 1940- P. A. CULLMAN 2,208,522

LIGHTING SEWING MACHINES AND THE LIKE Filed Sept. 3, 1956 4 Sheets-Sheet4 N N [A 10/ 5 I05 104 :5 If 102; E/ 1 m5 H H l i zw K78 m ugh b u! H ig (A III K I II a 1% W E14 f ATTORNEY Patented July 16, 1940 PATENTOFFICE azoaszz monme sswmo moms AND 'rnr:

rmup A. Cullman, New York, N. Y., asslgnor, by

meme assignments, to Lenslite notation of Florida 00. Inc., a cor-Application September 3, 1936, Serial No. 99,302 g 26 Claims. (01.240-214) This invention relates to lenses and light projectors, and moreparticularly to theircombination with and adaption to sewing machines.

The operation of sewing machines requires constant application to closework. At night under average or poor illumination the worker issubjected to much physical'and eye strain with a resulting lessening ofeiiiciency and health. To eliminate this condition by providing meansfor correctly illuminating the work tables of sewing machines is theprincipal purpose 01 this invention.

Another object of the invention is to provide a refractor suitable forproperly illuminating the table of a sewing machine.

A further purpose of the invention lies in the production of a refractorwhich when placed on or within a sewing machine will project a beamhaving its most intense portion at the needle or in a small area aboutthe needle on the work A further purpose of the invention is toilluminate the sewing machine table without glare in the eyes of theworkman.

Another object of the invention lies in the provision of differentlenses, reflectors and light projectors whichwil! be suitable formounting on different types of sewing machines.

Still another object of the invention is to provide light projectorsadjustable in position and efi'lcient in operation for use withsewingmachines.

Another purpose of the invention is to provide refractors and lightprojectors for use with sew-' ing machines harmonizing with theappearance of the machines and adding to their attractiveness.

A further purpose of the invention is to provide refractors andprojectors which will cheaply render adequate illumination for closework on sewing machines.

To aid a fuller understanding of the invention the accompanying drawingsare included in which Fig. 1 is perspective view of a baby model sewingmachine having mounted on its front side a refractor embodying theinvention. 1

Fig. 2 is a bottom view of the refractor alone. Fig. 3 is a verticalcentral section of the re- 5 iractor taken on line 20-40 of Fig. 2.

Fig. 4 is a vertical section of the refractor with hood added taken online 2l-2l of Fig. 3.

Fig. 5 is a diagrammatic representation showing the refractor in sectionand illustrating the paths of light rays from a source before and afterrefraction.

Fig. 6 is a perspective view of a portion of a sewing machine on whichis mounted a light projector adjustable in directions of light output.

Fig. 7 is a vertical central section of another lens and reflectorembodying the invention showing directions taken by light rays from asource before and after refraction and reflection.

Fig. 8 is a diagrammatic representation of the beam pattern on the tableproduced by the projector in Fig. 7.

Fig. 9 is a front elevation of still another lens embodying theinvention.

Fig. .10 is a horizontal sectional view of the lens taken on line 22-22of Fig. 9.

Fig. 11 is a section of the lens taken on line 2323 of Fig. 9 includinga reflector and housing with directions of light rays from a sourcebefore and after refraction.

Fig. 12 is a diagrammatic representative of a beam pattern on the tableproduced by theprojector in Fig. 11.

Fig. 13 is a vertical central section of still another lens embodyingthe invention drawn to scale half size with dimensions shown in inches.

Fig. 14 is a front elevation of the lens shown in Fig. 13 enlarged.

Fig. 15 is a vertical section of the lens taken on line 123-123 of Fig.14 and enlarged.

Fig. 16 is a vertical diagrammatic central sectional representation ofthe lens with light source and reflector added. 1

Fig. 17 is an enlarged vertical central section of the projector in Fig.16 showing the paths of light rays from a source before and afterrefraction.-

- Fig. 18 is a diagrammatic representation of a beam pattern on thetable produced by the projector in Fig. 16.

Fig. 19 is a section of a flat lens which may be used in place of therefractor shown in Fig. 3.

Referring more particularly to the drawings Fig; 1 portrays a refractor24 embodying the invention mounted on the front side of a small sewingmachine 25. Surmounting the refractor is a semi-cylindrical hood 26 atthe, rear end of which is a cylindrical projection 21 which serves tohouse the socket for an incandescent lamp.

The details of the refractor construction are clearly shown in Figs. 2,3, and 4. In designing refractive angles.

the refractor an incandescent fllament source of light is located at thepoint 26 in Fig. 3. From a point 26 located on the horizontal 1ine'HI-Icontaining the light source arcs 4| and 42 are drawn with radii RI vandR2 respectively. These arcs are merged into the horizontal straightlines 4| and 42 which form the inner and outer sides of the refractorelement of revolution. On the outside element 42 straight side prisms66-46 inclusive are formed each having the same width 46 but eachdiffering from the others in height andre-.

fractive angles. Straight line prisms 36-46 inelusive and 56-52inclusive are formed 'on the inner side 4| of the refractor element 24.All of these prisms are identical in width 43 but only prisms 46, 56,5|, and 52 are alike in height and Prisms 36, 61, and 66 each differfrom the others in these respects.

The element of the refractor 24 formed as above described is thenrevolved approximately vertically about the horizontal axis H-H, andapproximately 45 on each side of the vertical V-V as shown in Fig. 4.The shape of the refractor is then changed by the formation of a flatvertical side 44 extending approximately to the horizontal planecontaining the axis of revolution. The rear portion of one side iscontinued still higher to form flat vertical projections 45 with theslot 46 between them, Fig. 3.

Upon the forward spherical end of the refractor 24 thus formed areplaced vertical flutes 53-51 inclusive shown in Fig. 2. The center flute53 has the largest radius. Flutes 54 and 56 have equal and smaller radiiand flutes 55 and 51 have equal and still smaller radii.

The complete refractor is essentially a semicylindrical one open at therear end 41 Fig. 5 and closed at the front end by a-semi-sphericalsection containing external vertical flutes. External straight prismaticzones of refraction are formed on the under portion perpendicular to theflutes and internal straight prismatic zones of refraction are formed atthe rear end of the refractor.

In order to mount the refractor on a sewing machine a metal hood 26 Fig.4 having the same general shape as the refractor is flrst amxed to themachine by means of the screw 46. Referring to Figs. 1 and 4 arectangular, spring metal plate 56 is fastened to the hood 26 by meansof rivets 46. An incandescent tubular lamp 66 is inserted in the socket21 at the rear end of the hood 26. The refractor is'then slid up intoplace the slot 46, Fig. 3 providing room for the screw 46 and the springclip 56 fitting snugly about and under the flange 56 on the refractorholding it flrmly in place. The horizontal pressure produced by the clip66, on the projections 45, Fig. 3 prevents any displacement of therefractor without flrst releasing the clip 56.

Fig. 5 illustrates the action of the refractor in controlling light rayswhose paths are shown dotted. It will be seen that internal prisms 5|and 52 retract the incident rays traveling downwardly and to the rightin such manner that they emerge at angles closer to the verticalalthough still moving slightly to the right. Prisms 56, 46, and 36 throwthe emerged rays successively further and further to the left. Prisms36-36 inclusive converge thelight rays toward the position of the needle62 on the sewing table 6|. The spherical fluted portion of the refractorprojects light rays to the left of the needle, the flutes spreading themtoward and away from the worker. The retracting zones control and form abeam approximately 90 of solid angle in directions to and from thevertical plane containing the axis of the refractor. Thus the workingtable is illuminated fully by a beam having its most intense portion ina rectangular area about the needle where it is most needed. None of thelight is above the horizontal and therefore cannot create glare in theworkmans eyes which are above the refractor. The flat lens shown in Fig.19 may be used in place of the refractor 24.

The refractor with minor changes in design and size may be shifted inposition, placed in front or behind, on larger or smaller machines andmay even be incorporated in the lower part of the sewing machine arm 25and still accomplish its purpose of producing a better lightdistribution on the work table. The appearance of the refractor as abovedescribed is neat and attractive, completely harmonizing and adding tothe appearance of the sewing machine.

Another means of satisfactorily lighting the machine table is to mount alight projector entirely separate from the machine proper. This can bedone for example as shown in Fig. 6. Here a light projector consistingof a paraboloidal housing 63 and a lens 64 are mounted on the end of atubular arm 65 at the top end of which is located a universal ballandsocket' joint 66 supported in the arm 61 which is in turn supportedon the sewing machine table 6|. The universal joint 66 allows adjustmentof the light beam in any direction within approximately sphericaldegrees. With this arrangement the workman can adjust the light beam asbest suited to his 25 if desired or may be supported in any otherconvenient manner.

One embodiment of the projector used above is shown in Fig. 7 invertical central section. Here thelens 64 consists of concentric innerand outer spherical surfaces 13 and 14 respectively.

Formed on the inner surface are the annular rei'racting zones 66, 66, 1|and 12 and the bulls-eye 16. The rear apices of said retracting zonesfall in a spherical surface concentric with those of .the inner andouter faces of the lens. Prism 12 is straight in section but prisms 66,66, and 1| have curved incident sides formed by radii successivelyshorter from top to bottom. The centers for radii R66, R66, and theradius of the bull's-eye R16 lie on the axis of revolution of the lenssection H-H while the center for the radius of curvature of prism 1|,R1| lies below the axis of revolution. The substantially paraboloidalhousing 66 retaining the lens is plated and polished or otherwiseprovided with an inner surface of high reflecting power. The resultingpaths of rays-in accordance with the well known laws of reflection andrefraction are deputed in Fig. '1. Rays from the source 26 reflected bythe housing are shown dotted while those which are directly received onthe lens without previous reflection are shown in full line. Theselatter it will be noticed emerge from the lens converging slightlytoward the axis of revolution HH when refracted by the upper portion ofthe lens. Those refracted by the lower portion of thelens converge muchmore rapidly toward the axis of revolution resulting in an asymmetricbeam. The substantially parallel rays, striking the lens from thereflector housing, are, as shown, re-

angles, and cross the axis of revolution diverging rapidly.

When the projector is suspended above the table at a suitable height thebeam pattern on the table GI isas represented in Fig. 8. Here again 02represents the position of the needle. The intense portion of the beamconsisting of rays which are refracted only surrounds the needle 62.. Ofthis portion the part 15 comes from the lower portion of the lens and isbehind the needle. The area 10 is intensely lighted by refracted raysonly from the upper portion of the lens and is between the needle andthe workman. Surrounding the intense portion of the beam is the lowerintensity area 'II produced by rays both reflected and refracted whichsupply general illumination on the table. This beam pattern is ideal indistribution having the intense light exactly wheredesired aboutone-third back of the needle and two-thirds ahead of it and aspreviously explained the workman can adjust the position of theprojector to suit his requirementsand taste.

The lens above described is approximately three inches in diameter. Theinvention, however, is not limited to this particular size or shape.

The paraboloidal reflector can be changed in shape without materiallyaltering the general illumination obtained. A portion of it may even bemade diffusely rather than specularly reflecting without sacrificing andperhaps bettering the characteristics of the beam.

- Another lens I8 embodying the invention which may be substituted inthe projector for the one I above described is shown in Figs. 9, 10, and11. This lens is round having a flat rear surface upon which are formedvertical flutes 95, Fig. 10for the purpose of changing the round beampattern into a rectangular one. Upon the outer surface of the lens areformed horizontal straight prismatic retracting zones 8I-92 inclusive.In the center of the outer surface of the lens 18 are formed annularprismatic zones 93 and 94 differing from each other in refractiveangles. The corresponding horizontal prisms of the upper half of thelens are similar to those of the lower half thus giving a symmetricalbeam but each prism of one portion of the lens differs from every otherof the same portion in refractive angle. Thus prism 86 differs from eachof prisms 8|, 82, 83, 84, and 85, but is exactly the same as prism 92 inthe lower half of the lens. The prisms increase in refractive power thefurther they lie from the center of the lens. The innersides of allprisms are parallel to the paths of rays through the lens in theirrespective positions. This features causes all of the rays from thesource proceeding directly to the lensto be eificienctly refracted inthe desired directions without production of any stray light refractedfrom the inner sides of the prisms, I

In Fig. 11 the lens is assembled in a cylindrical housing 96 flanged atone opening to contain it. A wire retaining ring 91 holds the lens inplace. A spherical reflector 95 having its center at the focus 28 of thelens is also used. The inner forward portion of the housing 90 ispolished to form a reflecting surface and the whole unit mounted insimilar manner to the projector shown in Fig. 6. In Fig. 11 the solidlines represent paths of rays directly striking lens from the source 28which is placed at the focus of the lens and the rays reflected by thespherical reflector. These rays emerge concentrated and parallel andform the intense portion 80 of the beam pattern shown in Fig. 12. .Here62 again represents the position of the needle on the sew-' ing tableGI. The. dotted lines Fig. 11 represent the paths of raysstriking thehousing which are reflected and refracted to emerge from the lensv twidely diverging angles to form the low intenity portion of the beampattern 99 in Fig. 12..

If the housing is made diffuse reflecting, a-better beam is obtained.The oval shape of the beam is occasioned by the vertical flutes 95previously mentioned. I I

Still another lens embodying the invention and which may be substitutedfor the lenses above described in a separate projector is shown in Figs.13-17 inclusive. Referring to Fig. 17 more particularly, the lens I isshown in -section. The mechanics of its design consists in choosing arectangular vertical section I 00 and forming at its ends the rearwardlyprojecting flanges IOI. A circular arc I02 is drawn on the outside withradius RI2 and center on the hori zontal H-H containing the focus 28.Two prisms 7 I03 and I04 are drawn on the innerside at its top. Theincident sides of these slope 2 away from the horizontal to-allowwithdrawal of the manufacturing plunger. These prisms are made totalinternal reflecting by forming their upper sides with long radii RI3 andRI4 having centers below and to the right of the lens. Two similarprisms H0 and I09 are constructed on the bottom of the inner surfacethese having reflecting sides formed by still longer radii R20 and RI 9above and to the right of the lens. Below prism I04 is constructed therefracting prism I05 having a short radius with its center on H-H. A

. similar prism I08 is formed below having a slightly longer radius butwith center on H H. Refracting zones I06 and I0! are then formed bydrawing arcs with unequal radii RIG and RI I having different centers inHH. RI'I be vthe outside face of the lens as shown in Figs. 14

and 15. Flute H3 is the only simple radial flute and is formed on thebull's-eye I02 with radius of curvature R23. Flutes I I2 and I I4 aretransitions between flutes and prisms having sections which are straightlines merging into arcs with radii R22 and R24 respectively. Of thesetwo the latter is the longer being on the upper portion of the lens. Thestraight portion of the external surface contains five equal flutes IIIwhich are also partially prismatic. Their radial surfaces are formedwith radius R2I.

The functions of these prisms is to spread the beam vertically. Inaccomplishing this purpose the prismatic portions of the flutes tend toconverge diverging rays toward paths substantially parallel with thehorizontal H--I-I. The radial portions of the flutes diverge the lightvertically up and down, flute II2 causing slightly more divergence thanflute I I4. of the flutes tends to even the intensity of the beam andeliminate prism striations.

The lens I00 may be assembled in a projector as shown in Fig. 16. Thehousing here consists of a semi-spherical upper portion II5 formed bythe revolution 180 about HH of an are having radius R30 and center I30below H-H and The diffusing nature is turned at the other end to housethe socket for lamp 80. v

The dotted linw in Fig. 17 illustrate the paths of light rays before andafter refraction by lens I00. Internal reflecting prisms I03, I00, I09,II0, it will be noticed-produce rays diverging from HH diverging atslightly greater angles from the lower portion of the lens than from theupper. Refracting zones I05 and I08 take direct light from the source 28and cause it to emerge in paths practically parallel ,with the axis ofrevolution HH, while rays controlled by zones I01 and I08 emerge atsmall divergent angles with HH. The net result is to produce aconcentrated beam which is asymmetric tending to wider spread and lessintensity in the portion produced by the lower half of the lens. Theinner sides H5. and III of the housing being plated and polished to forma reflecting surface produce a general widespread illumination of lowintenuse on larger sewing machines.

of the beam." Light from upper portion I I5 is reflected downwardlyundergoes refraction and emerges from the lens downwardly at largediverging angles with HH. Similarly light reflected by the lower portionof the housing I" diverges upwardly at large angles.

The resulting beam pattern is clearly shown in Fig. 18 where again IiIrepresents the sewing table and 62 the position of the needle. It willbe noticed that when the projector is placed as in Fig. 6 and adjustedthe very intense smaller portion of the beam II! from the upper half ofthe lens surrounds the needle. lower intensity and larger portion of thebeam from the lower half of the lens I20 is in front of the needle onthe work about to undergo the sewing operation while the low intensitygeneral illumination I2l proceeds from the reflector. It is the flutespreviously mentioned which produce the elongated characteristics of thebeam pattern. Should it be chosen to leave them off, the pattern wouldconsist of two semi-circles of high intensity light of different radiisurrounded by two semi-circles of low intensity light of differentradii. However, the elongated oval shaped beam is more desirable asexplained in connec--' tion with the projector described in Fig. 'I.

Should it be desired to make both halves of the lens alike, theresulting beam pattern will of course be symmetrical.

While a detailed portrayal has been given of some of the forms theinvention may take not only in its optical characteristics but also itsmechanical features, it is not intended to limit the invention to theabove description. The; efflciency in quantity and quality ofillumination obtained, and the beauty and harmony of appearance of thesmall projectors described will not be sacrificed in the design oflarger ones for I Changes in the number of prisms placed on therefractor or changes in refractive angles, curvatures and centers ofcurvatures of prisms and lens to produce a similar type of beam whenprojectors are changed in mounting heights or otherwise changed inposition may be made without de- The slightly I claim: I I

1. In combination with a sewing machine, a

light projector mounted thereon, including an' electricallyenergizedlight source within said projector and a lens, said lens having lightcontr'ol'means to direct a restricted and concentrated beamof lightdownwardly upon the needle working position of said machine, and othermeans to allow light to pass therethrough to provide light of lesserintensity around the area illuminated by the concentrated beam;

2. In combination with asewing machine, a light projector mountedthereon, including an electrically energized light source within saidprojector and a lens, said lens having light control means to direct aconverging concentrated beam of light'downwardly upon the needle workingposition of said machine, and other portions to allow light to passtherethrough to provide light of lesser intensity around the firstmentioned beam.

3. In combination with a sewing machine, a light projector mountedthereon, including an electrically energized light source within saidprojector and a lens, said lens having light control means to direct abeam of light, the cross section of which is elongated in a directionsubstantially in line with the work path of the machine, upon the needleworking position of said machine, and other portions to allow light topass therethrough to provide light of lesser intensity around the firstmentioned beam.

4. In a sewing machine, means for illuminating that area of the machineincluding and surrounding the needle; said means including a lightsource and refractor, said refractor having a light control zone soconstructed as to concentrate a beam of light of greater intensity onsaid area and other portions so constructed as to produce a divergentbeam of lesser intensity to illuminate a relatively larger area aboutthe first mentioned area.

5. The combination with a sewing machine, of a prismatic refractormounted on the machine, a light source therefor, the refractor includingmeans to divide light rays passed therethrough, a

centrally located section of said means refracting illuminate partssurrounding said part of the machine. I

6. In a sewing 'machine, a plane work table surrounding a minor area formechanical operation upon material guided thereto, means forilluminating said minor area and a surrounding area on said work-table,the minor area receiving the most intense illumination from said means,said illuminating means being mounted above said work-table andincluding a lens, a light source in the rear of said lens and lightcontrol zones so formed on said lens that light from said source ispartially concentrated at said minor area along the path of travel ofwork on said machine, while light passing through the remainder of thelens is spread over said surrounding area.

7. A controllable mechanism including a plane work-surface surrounding aminor area for mechanical operation upon material guided thereto, meansfor illuminating said minor area and a surrounding area on saidwork-surface,

said illuminating means being mounted above said work-surface andincluding a lens, a light source behind said lens, prismatic surfacesformed in said lens and so oriented relative to each other as to directa concentrated light beam and to elongate said light beam substantiallyin the direction of travel of material to be worked upon and forproducing a light of lesser intensity surrounding said elongated area. v

8. The combination with a horizontally disposed work surface acrosswhich work is to be fed, of a light source positioned above saidsurface, a reflector enclosing the upper side of said light source and aprismatic refractor enclosing the under side of the light source andhaving light control zones to direct its rays downwardly within an areasubstantially less than that of the work surface, one of said zonesacting to project a concentrated light from said source upon arelatively small area of the illuminated portion of the surface, saidarea being elongated substantially in line with the path of travel ofthe work, and other of said zones acting to illuminate with a lesserintensity a relatively larger area of the illuminated portion of thesurface about said concentrated beam.

9. In combination, a controllable mechanism having a definite workingstation and means for projecting an intense light of relatively smallarea upon said working station and a light of relatively less intensitybut covering a sub stantially greater area, immediately adjacent saidworking station and surrounding said area of intense light, both of saidlight areas being elongated in the direction of and substantially inline with the path of travel of work to be fed to said working station.

10. In a machine for working upon material fed thereto, a definiteworking station across which work is to be fed, means for projecting anintense light covering a relatively small area at said working station,the intense light being divided into a plurality of immediately adjacentzones of varying intensities; and a light beam of relatively lessintensity bounding the intensity illuminated area.

11. A manually controllable mechanism including a plane work-tablesurrounding a minor area of mechanical operation upon material manuallyguided thereto, means for illuminating said minor area and a surroundingarea on said work-table, the minor area receiving the most intenseillumination from said means, said means including a lens so mountedthat its axis is parallel to the work-table, a light source mounted onsaid lens axis, prismatic surfaces formed in the lens transverse of itsaxis and so oriented relative to each other that light from said sourceis concentrated about said minor area while light passing the remainderof the lens is spread over said surrounding area.

12. A semi-cylindrical lens with horizontal axis of revolution, open atthe top and one end, a spherical portion closing the other end, andinternal and external prisms transverse to the axis of revolution formedupon the cylindrical portion.

13. A semi-cylindrical lens with horizontal axis of revolution open atone end and closed at the other by a spherical portion, a reflector,said lens having a plurality of inner and outer prismatic zonestransverse to the axis of revolution of diflerent refractive powers soformed on said cylindrical portion that light projected by saidreflector from a source passes through said lens for concentration inone zone and diffusion in an adjacent but larger zone.

14. In combination, a sewing machine including a work surface and alight projector mounted in such manner as to effectively illuminate thework surface of said machine with a beam having its highest intensity inthe small area surrounding the needle of said sewing machine, said lightprojector comprising a lens whose axis of revolution is horizontal aplurality of prismatic zones transverse to the axis of revolution formedupon said lens, and a light source within the axis of revolution of saidlens.

15. In combination with a light source, a semicylindrical lens withhorizontal axis of revolution, open at its top and at one end and havinga sub stantially spherical portion at its other end, and internal andexternal prisms transverse to the axis of revolution formed on thecylindrical portion, said prisms being arranged to form adjacent lightcontrol zones, one of said zones being constructed so as to project aconcentrated beam of light of maximum intensity from said source and theother of said zones so as to pro ject diffused light of a relativelylarger area and lesser intensity about the first mentioned light beam.

16. Alight projector comprising a lens having a semi-cylindrical portionwith horizontal axis of revolution, a light source within said axis ofrevolution, a housing above said lens and having a reflecting surfaceadapted to direct light from said source downwardly of said lens, and apinrality of prismatic zones formed on the said lens transverse to saidaxis' of revolution so that the projected light is concentrated in onezone and diifused in an adjacent but larger zone that is substantiallysymmetrical with respect to said concentrated zone. 1

17. A light projector comprising a lens having a semi-cylindricalportion with a horizontal axis of revolution, a light source within saidaxis of revolution, a housing above said lens and having a reflectingsurface adapted to direct light from said source downwardly of saidlens, and a plurality of prismatic zones formed on said lens transverseto said axis of revolution, so that the projected light forms anasymmetrical field having immediately adjacent zones of concentratedlight of different intensities and a symmetrical zone of diffused lightof a lesser intensity surrounding said concentrated zones.

18. In a sewing machine, a light projector mounted thereon, saidprojector comprising an apertured housing with an internal reflectingsurface substantially paraboloidal in shape,.a light source at the focusof said reflecting surface, and a lens, closing the aperture of saidreflector housing, having a plurality of annular refracting zones,prismatic and toroidal in shape, of different curvatures and centers ofcurvature, so

formed upon the inside surface of the said lens A as to converge thedirect rays from said light source toward the optical axis of saidprojector, a greater convergence being produced by onehalf of the lensthan by the other.

19. In combination: a sewing machine, a light projector mounted abovesaid machine comprising: an apertured housing having an internalreflecting surface, a light source at the focus of said reflectingsurface, and a lens closing the aperture of said housing, said lenshaving a plurality of internal annular refracting zones, of differentcurvatures and centers of curvature, and so related as to converge thedirect rays from the light source toward the position of the needle onthe table ot the said sewing machine.-

20. In a sewing machine, a light projector including a lens, said lenshaving a plurality of retracting zones and a plurality oi totalreflecting zones, one portion of said lens diflering from acorresponding portion and each retracting and reflecting zone difleringfrom the others, said zones being oriented realtively to one another soas to project a concentrated light field about the needle of saidmachine.

21. In a sewing'machine, a lens having a pin-- rality of retractingzones and a plurality of total reflecting zones, the upper portion ofsaid lens difiering from the lower and each retracting and reflectingzone diiterlng from the others, toroidal surfaces on said zonesdiitering in curvature and centers of curvature, and a bull's-eye formedupon the outer surface of said lens to produce a more brilliantlyilluminated central portion in a light beam from said lens.

22. In a sewing machine, alens having a pluferent-ceriters displacedfrom the axis of revolu-- tion and whose inner surface is a reflectingsurface, a light source in the axis of revolution of said housing, and alens flanged inwardly closing the aperture of said housing, a pluralityof projector mounted above said machine, said light projector comprisinga light source and a lens with a plurality of retracting and totalreflecting zones oriented in such manner as to project the direct lightfrom said source in an elongated concentrated beam onto the areacontaining the needle position in the table of said sewing machine.

25. A means for illuminating that area of a sewing machine including andsurrounding the needle, consisting in a light source mounted on themachine and a prismatic refractor formed to provide annular retractingzones of different curvatures and different centers of curvature to Idirect the light rays from the light source with maximum intensity uponthe needle and the area immediately surrounding the needle.

26. Ina light projector, a lens comprising a plurality of retractingzones and a,plurali ty of total reflecting zones, the total reflectingzones being separated by the retracting zones, a light source in theoptical axis of said projector, and horizontal flutes formed upon theouter surtace ot the lens, said reflecting and retracting zones and saidflutes being oriented in relation to each other so as to converge thedirect light from said light source into an oval beam elongatedvertically in two elliptical parts in which the part from one portion ofsaid lens has larger minor and major axes than the respective axes ofthe part from the other portion of the lens.

PHIIIPP A CULLMAN.

